1. Field
The present disclosure relates generally to transformers and, in particular, to autotransformers. Still more particularly, the present disclosure relates to a multi-phase autotransformer having a configuration that improves harmonic mitigation.
2. Background
Some devices are powered using direct current (DC) power, while other devices are powered using alternating current (AC) power. In certain applications, power sources that provide alternating current power are used to supply power to electrical components that require direct current power. Typically, in these applications, alternating current power is converted into direct current power using a transformer.
As one illustrative example, a power generation system for an aircraft may include power sources that are used to supply power to electrical components onboard an aircraft. These power sources are typically alternating current power sources. The power sources may include, for example, without limitation, any number of alternators, generators, auxiliary power units, engines, other types of power supplies, or combination thereof. The alternating current power provided by these power sources may be converted into direct current power that may be sent to any number of electrical components onboard the aircraft. The electrical components may include, for example, without limitation, a locking mechanism, a motor, a computer system, a light system, an environmental system, or some other type of device or system on the aircraft.
However, converting alternating current power into direct current power may lead to undesired harmonics, which may, in turn, lead to undesired harmonic distortion of the power generation system, power distribution system, or both. Harmonics are currents and voltages at frequencies that are multiples of the fundamental power frequency. Reducing harmonics, and thereby, harmonic distortion, may reduce peak currents, overheating, and other undesired effects in electrical power systems.
Some currently available multi-phase transformers, including zigzag transformers, may be used in electrical power systems to reduce harmonic currents, and thereby, harmonic distortion. However, the level of harmonic mitigation provided by these currently available transformers may not reduce harmonic currents to within selected tolerances. Consequently, additional electrical devices, such as filters, may need to be used in the electrical power systems. However, these additional electrical devices may increase the overall weight of the electrical power systems more than desired. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.